Ground Source Heat Pumps: Our Experience in Harrogate Andrew Ellis - PowerPoint PPT Presentation

Ground Source Heat Pumps: Our Experience in Harrogate Andrew Ellis Environmental Strategy Officer Harrogate Borough Council Andrew.ellis@harrogate.gov.uk

Achievements in Pilot • Running costs approx £250-£300 per year for hot water and central heating, 24/7, in on or off gas situations. • Reduces CO2 by at least 30-50% in on and off gas situations • Meets fuel poverty targets and future proofs properties

Harrogate Borough Council ground source heat pump progress in retrofit situations • Pilot scheme installed July 2005: 8 domestic properties • Steep learning curve of all parties; suppliers, installers, local authority, householders- good results! • Tenants • Met fuel poverty targets provided 100% heating and hot water • lower running costs • Future proofed properties • Provided off gas solution • For the housing provider -reduced running and future installation costs • local and National Targets – Off gas reduced CO2-- 75%:

Choice of renewable technology governed by • Largest impact on existing houses after all low cost insulation achieved. – Heating and hot water 82%, water 22% • Holistic solution for water and heating • Alternatively available local energy source • Cost per unit of energy delivered

To obtain efficiency with a heat pump • The temperature variation from the source to the emitter ( delta t) should be as small as possible. • Keeping it small allows the heat pump to operate at a more efficient part of its performance curve i.e. with a greater COP

Solar impact on earth temp Source: Viessman technical manual

Horizontal panel array

Vertical Panel Array

• Evaluation and dissemination to local authorities and housing associations, private sector housing • Copt Hewick pilot scheme open day • Case studies, reports -on line • Media local regional and national • Grant, plus supplier support, organised for 4 units installations in local housing association where HBC has nomination rights.

Copt Hewick Open Day 90 people from 35 organisations represented. All tenants attended, two coach loads of visitors. Morning and afternoon sessions

Vertical borehole Installation

Using a larger drill option for borehole

• Mass installation scheme : target 100; commenced 2007 • Currently total 93. In addition-Through grant support for redevelopment a pilot in high insulation construction of air to air heat pump using inverter technology Installed 4 units Dec 2007

Eight vans eight installation teams

Drilling and cleaning

What we have found • Heat pumps produce a different type of heat. More evenly delivered and stable. • This takes some getting used to! • People have been used to rapid introduction of high temperature heat, • Ultimately it is better and cheaper .

Electricity Meter Results • Our longest running installations now have average total house energy consumption of approximately 6200kwh p.a. • SAP would suggest 9500kwh for heating and national average for other appliances is 3500kwh. So the normal total for this property size 13,000kwh • Some properties used less, some more. Some households may require higher temperatures. • Retired active single males use the least energy. Totals of around 4500 - 4800kwh per annum, this is for heating hot water and full household appliances have been achieved .

Energy consumption comparison for heating/dhw, with gshp, in properties with and without building fabric improvements to maintain set temperature. Table 1 Low building fabric High building fabric Property type performance performance Calculated Energy Calculated Energy property heat consumed property heat consumed requirement by GSHP requirement by GSHP (Ave kWh (Ave kWh (Ave kWh (Ave kWh p.a.) p.a.) p.a.) p.a.) Bungalow 12,000 3,601 9,500 2490 House 17,000 5,224 11,500 n/a

Constraints and advantages • No planning constraints- Although the ability to install ground loops outside the domestic curtledge, as gas pipes are, may be of value • Capital cost • Cash flow- up front cost • Heat pumps have long life, 25 years. • Whole life costings similar to existing system options, but with higher up front cost.

ESCo model • Separate organisation capitalises the technology and owns the equipment. The ESCo then receives incentives over time which repay capital cost. • ESCo run by local authority. It sets up equipment with a technical supplier/s. It tenders for group purchasing of fuel for its clients. • ESCo fits heat pumps/solar thermal / Photovoltaic panels on properties roofs. Reduction achievable 80% • Operates on edge of areas where property density favours district systems. • District systems using recovered heat from waste water, biomass and fossil fuel top up. Systems such as this have been run successfully in Sweden’ for the last 25 years, using British technology funding local authorities.

Future technological developments Heat recovery and cooling Linking to solar panels Ground charging

• Future work • Developing a sustainable business as usual structure for delivery implementation • Group purchasing plan • ESCo • Advice support system tenants • Advice support grants installation training for installers In conjunction with local Energy Efficiency Advice Centre for North Yorkshire- Ryedale Energy Conservation Group

Solar driven solution Locally sourced Reducing emissions by at least 80% Solution First Insulation ground sourced heat pump. solar panel, solar photovoltaic panel.